Fundamentals of Computer Architecture. A Review Of Chapters 1 to 7

Transcription

1 Fundamentals of Computer Architecture A Review Of Chapters 1 to 7 1

2 OVERVIEW This presentation includes: Introducing The Processor Fundamental Concepts I - Data Representation Fundamental Concepts II - Digital Electronic Circuits Registers The ALU Buses Memory 2

3 Introducing The Processor Computer are everywhere Definition: It must take input of some sort; It must produce output of some sort; It must process the information somehow; It must have some sort of information store; It must have some way of controlling what it does. Most computers are embedded in other devices 3

4 Introducing The Processor A von Neumann architecture, We need: A processor - to process information, and to control the system; Memory - for data and instruction storage; Some form of input device; Some form of output device. 4

5 Introducing The Processor To build our simple processor we need the following components: Some Registers - a register is a store where we can place one piece of data; An Arithmetic Logic Unit, or ALU - a very basic calculator for our processor. A Control Unit, or CU - to run the processor; Some buses - to allow us to move data from one component to another. 5

6 Introducing The Processor 6

7 Fundamental Concepts I - Data Representation We covered: Number representation - decimal, binary, octal, hexadecimal and Binary Coded Decimal (BCD); Conversion between different bases; Binary arithmetic; Signed representations - sign and modulus, 1 s complement, 2 s complement and floating point; Logic operations - AND, OR and NOT; Data representation - ASCII and Unicode. 7

8 Fundamental Concepts I - Data Representation The simple rule for obtaining the 2 s complement representation of the negative of a number is Flip the bits Add 1 8

9 Fundamental Concepts I - Data Representation Now we know how to figure out the representation of a negative number, let s try some arithmetic 9

10 Fundamental Concepts I - Data Representation 10

11 Fundamental Concepts I - Data Representation 11

12 Fundamental Concepts I - Data Representation ASCII For example, the ASCII code for the letter R is found as follows: The column that R is in is labelled with the hexadecimal digit 5; The row that R is in is labelled with the hexadecimal digit 2; This produces the hexadecimal value ASCII is being replaced by 16- bit Unicode. 12

13 Fundamental Concepts II - Digital Electronic Circuits We covered: Gate logic - AND, OR and NOT; How to build circuits with gates; Modelling circuits with truth tables; Boolean algebra, including De Morgan s laws. 13

14 Fundamental Concepts II - Digital Electronic Circuits 14

15 Fundamental Concepts II - Digital Electronic Circuits NAND NOR XOR 15

16 Fundamental Concepts II - Digital Electronic Circuits A circuit diagram can be derived from a truth table 16

17 Fundamental Concepts II - Digital Electronic Circuits Boolean Algebra The set of rules that we can make use of are known as the identities of boolean algebra. Each identity (apart from the absorbtion and double complement) has two forms, one for the AND form, and the other for the OR form. 17

18 Fundamental Concepts II - Digital Electronic Circuits Boolean Algrebra De Morgan s Laws can help us in the creation of efficient digital circuits. 18

19 Registers We covered: Bistables - the RS latch, the D latch and the D flipflop; How to build a register; Tri-state logic; The concept of a clock and a clock cycle. 19

20 Registers The RS Latch 20

21 Registers The D Latch 21

22 Registers The D Flip-flop 22

23 Registers A 4-bit register A 4-bit register attached to a bus 23

24 Registers To move a bit pattern from register 1 to register 2 we would do as before: Set register 1 OE to 1 (bit pattern now on the bus); Clock register 2 (for register 2 to take the bit pattern from the bus); Set register 1 OE to 0; 24

25 Registers The Clock cycle There are effectively four different types of trigger. These are: 1 triggered - when the clock signal becomes 1; 0 triggered - when the clock signal becomes 0; Positive edge triggered - when the clock signal changes from a 0 to a 1; Negative edge triggered - when the clock signal changes from a 1 to a 0. 25

26 The ALU We covered: The role of the ALU and PSR within the processor; The control circuitry of the ALU; Adder circuits - the half adder and the full adder; Building circuits to demonstrate the functionality of the ALU the ADD, SL and NEG circuits. 26

27 The ALU 27

28 The ALU 28

29 The ALU Half Adder Full Adder 29

30 The ALU The ADD circuit 30

31 Buses We covered: Processor buses - the data bus, the address bus and the control bus; Building a bus with gate logic; Timing diagrams. 31

32 Buses 32

33 Buses A timing diagram 33

34 Memory We covered: The concepts of memory; How to build memory from gate logic; Types of memory; Address decoding strategies; Memory maps. 34

35 Memory A small memory A D flip-flop 35

36 Memory 36

37 Memory 37

38 Memory Building wider memories Partial address mapping 38

39 Memory JASPer memory 39